The present invention relates to a laminated shim for a disc brake arranged between a pad for a disc brake and a pressing member for pressing the pad against a rotor.
A disc brake device strongly clamps a rotor from both sides in an axial direction by a pair of pads and performs braking by friction force acting on abutting portions between linings configuring the pads and both axial side surfaces of the rotor. At the time of such braking, an attitude of the pad tends to become unstable since a portion of the pad where the friction force acts on and a portion where the pressing member such as a piston or a caliper claw part presses the pad are displaced by a thickness of the pad. When the attitude of the pad becomes unstable, the pad vibrates and generates noise called squeal, and uneven wear tends to occur on the lining. In the present description, the axial direction, a circumferential direction and a radial direction refer to an axial direction, a circumferential direction and a radial direction with respect to the rotor unless otherwise specified.
In order to suppress the squeal and uneven wear, a shim is usually clamped between a back surface of a pressure plate and a pressing member that presses the back surface. The shim may be a single plate shim formed by one shim plate, or a laminated shim formed by laminating a plurality of shim plates so that an effect of suppressing the squeal and uneven wear is improved. A plurality of structures are known for the laminated shim, for example, JP 2010-031960 A discloses a structure in which a pair of laminated shim plates is bonded by an adhesive.